1. Field of the Invention
The present invention relates to an actuator of a clutch, and more particularly to an actuator for operating a clutch in a transmission of an electric vehicle.
2. Description of Related Art
Generally, an actuator converts electrical energy, hydraulic energy or pneumatic energy to a mechanical energy. The actuator is used to operate a clutch of a transmission.
In a case of a manual transmission, a clutch control system of a clutch release cylinder type or concentric sleeve cylinder type is used.
In the clutch release cylinder type, if a driver pushes a clutch pedal, hydraulic pressure is generated in a clutch master cylinder and a tappet of a clutch release cylinder is operated by the generated hydraulic pressure.
At this time, the tappet pushes a clutch release fork so as to move a clutch release bearing in an axial direction. After that, the clutch release bearing moved in the axial direction operates a clutch diaphragm spring.
In a case of an automatic transmission, a clutch actuator is adapted to engage and release the clutch automatically. The clutch actuator of the automatic transmission receives a signal from an electric control unit (ECU) so as to operate the clutch. The clutch actuator has a master cylinder, a device for converting a motion direction and a motor.
The master cylinder is connected to a slave cylinder disposed around a release device of the clutch. The device for converting a motion direction includes a rod, a worm wheel and a worm gear. The rod contacts with a piston of the master cylinder. The worm wheel is fixed to an end portion of the rod. The worm gear is coupled to the worm wheel and is fixed to a rotating shaft of a motor. That is, if the motor rotates, the worm wheel is rotated by rotation of the worm gear. Thereby, the rod is moved linearly and the piston of the master cylinder is operated. Therefore, the hydraulic pressure is supplied from the master cylinder to the slave cylinder, and the slave cylinder is adapted to operate the release device so as to engage or release the clutch.
However, since the number of the components including conventional clutch actuators is many, a cost may be increased and a spatial utility may be deteriorated.
The information disclosed in this Background of the Invention section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.